Busbars: Overcoming Overcurrent at Copper Joints
In the fast-growing new energy sector, from EVs to energy storage systems, busbars are the critical pathways for power transmission. Among them, copper busbars are widely used for their excellent conductivity and mechanical strength. However, overcurrent at the joint interfaces remains a hidden risk that threatens system safety and efficiency.
1. Overcurrent at Copper Joints: A Critical Weak Point
(1) Heat Generation & Current-Carrying Limits
According to Joule’s Law (Q = I²Rt), copper joints generate additional heat due to contact resistance. Standards such as GB/T 7251.1 (IEC 61439-1) limit the temperature rise of copper conductors to 105K, capping working temperature at 140°C. Exceeding this threshold risks annealing, reduced strength, insulation degradation, or even fire.
(2) Current Surge Under Complex Conditions
EV battery systems face fluctuating currents—steady at ~200A, but spiking to 600A during fast charging. Using the short-time withstand current formula S = (I/13) × √t, joints must be designed for peak loads. Meanwhile, high temperatures and humidity raise resistance and contact oxidation, further stressing joint performance.
(3) Rising Demands from Industry Trends
Energy storage and EV systems are pushing toward higher power density. Within five years, battery copper busbar current requirements are projected to increase by 30–50%. As demand grows, joint overcurrent tolerance has become a limiting factor in system design and performance.
2. RHI’s Solution: High-Performance Busbars with Reliable Joints
(1) Advanced Welding for Superior Conductivity
RHI operates over 30 precision polymer welding machines and multiple automated lines, supporting copper-copper and copper-aluminum busbars. By optimizing weld temperature, time, and pressure, joint resistance is minimized—enhancing conductivity and thermal stability.
(2) Custom Solutions for Demanding Applications
Our engineering team provides tailored insulated busbar and bare busbar designs based on current, space, and environmental needs. Simulations ensure optimal current-carrying capacity, temperature control, and mechanical strength. For high-load applications, we increase cross-sectional area or use parallel joints; for tight spaces, compact layouts are deployed.
(3) Total Quality Control for Reliable Performance
RHI implements strict quality checks from material sourcing to final testing. Copper purity and conductivity are verified, and CCD systems inspect dimensional accuracy. Joint resistance is measured point-by-point with automatic alerts. Final products undergo current surge, temperature cycling, and durability testing to ensure long-term reliability.
Through advanced process control, customized engineering, and rigorous QA, RHI delivers high-performance copper busbars built to meet the demands of next-generation energy systems.
